Innate immune system The innate immune system, also known as the nonspecific immune system and the first line of defense,[1] is an important subsystem of the overall immune system that comprises the cells and mechanisms that defend the host from infection by other organisms. The cells of the innate system recognize and respond to pathogens in a generic way, but, unlike the adaptive immune system (which is found only in vertebrates), it does not confer long-lasting or protective immunity to the host.[2] Innate immune systems provide immediate defense against infection, and are found in all classes of plant and animal life. They include both humoral immunity components and cell-mediated immunity components. The innate immune system is an evolutionarily older defense strategy, and is the dominant immune system found in plants, fungi, insects, and primitive multicellular organisms.[3] The major functions of the vertebrate innate immune system include: Anatomical barriers[edit] Inflammation[edit] Mast cells[edit]
Greffe de matière fécale : une efficacité confirmée ( 5 Votes ) Les fidèles d’EurekaSante.fr s’en souviennent certainement. Il y a quelques mois, nous avions publié un article sur une méthode nouvelle et originale visant à traiter des diarrhées dues au germe Clostridium difficile. Des auteurs canadiens ont entrepris de faire le point sur les connaissances mondiales dans le domaine de la « greffe » de matière fécale (également appelée bactériothérapie fécale). Les auteurs notent cependant que l’efficacité varie en fonction de la technique d’administration, des caractéristiques du donneur, du volume de selles administré et du traitement prescrit préalablement au patient. Des travaux sont encore nécessaires pour comprendre le mode d’action de ce traitement et définir des protocoles thérapeutiques précis. Source : Gough E et al : Systematic Review of Intestinal Microbiota Transplantation (Fecal Bacteriotherapy) for Recurrent Clostridium difficile Infection.
Skin flora Depiction of the human body and bacteria that predominate A major nonhuman skin flora is Batrachochytrium dendrobatidis, a chytrid and non-hyphal zoosporic fungus that causes chytridiomycosis, an infectious disease thought to be responsible for the decline in amphibian populations. Species variety[edit] Bacteria[edit] The estimate of the number of species present on skin bacteria has been radically changed by the use of 16S ribosomal RNA to identify bacterial species present on skin samples direct from their genetic material. Staphylococcus epidermidis and Staphylococcus aureus were thought from cultural based research to be dominant. ecology of the 20 sites on the skin studied in the Human Microbiome Project There are three main ecological areas: sebaceous, moist, and dry. Fungal[edit] A study of the area between toes in 100 young adults found 14 different genera of fungi. Umbilical microbiome[edit] Relationship to host[edit] Another aspect of bacteria is the generation of body odor.
Microbiome Ensemble des génomes des bactéries colonisant l'organisme d'un animal. On les considère collectivement pour une raison essentiellement pratique. Plutôt que de séquencer successivement les génomes de toutes les espèces bactériennes, on utilise les méthodes de la métagénomique, applicable à un écosystème complet. Les bactéries qui vivent en commensalisme avec le corps des animaux y jouent des rôles très importants, notamment pour la digestion et la défense contre les organismes pathogènes. On estime que les bactéries hébergées par le corps humain sont environ dix fois plus nombreuses que ses propres cellules. connexes
Hologenome theory of evolution The hologenome theory of evolution proposes that the object of natural selection is not the individual organism, but the holobiont, i.e. the organism together with its associated microbial communities. Precursor: coral probiotic hypothesis[edit] Unbleached and bleached coral The hologenome theory of evolution originated in studies on coral reefs. Over the past several decades, major declines in coral populations have occurred. Coral bleaching is the most serious of these diseases. The surprise stems from the knowledge that corals are long lived, with lifespans on the order of decades,[6] and do not have adaptive immune systems. Extrapolating the Coral Probiotic Hypothesis to other organisms, including higher plants and animals, led to the proposal of the Hologenome Theory of Evolution. Hologenome theory[edit] Definition[edit] The principles of the hologenome theory of evolution are as follows (condensed from Rosenberg et al., 2007):[9] Primary versus secondary symbionts[edit] Criticism[edit]
L'étrange flore intestinale des chasseurs-cueilleurs Le peuple hadza est l’un des derniers peuples africains à vivre encore de la chasse et de la cueillette. Un mode de vie qui change leur flore intestinale et qui nous poussent à revoir quelles sont les bonnes et les mauvaises bactéries commensales. © Woodlouse, Flickr, cc by sa 2.0 L'étrange flore intestinale des chasseurs-cueilleurs - 2 Photos Nos entrailles constituent un terrain de jeu privilégié pour de nombreux micro-organismes. Elles sont si importantes qu’il est souvent préconisé de reconstituer les populations disparues après une prise d’antibiotiques ou des diarrhées, à l’aide d’une alimentation saine et équilibrée, ou avec des probiotiques, des compléments alimentaires contenant des bactéries. Le profil microbiotique idéal pourrait-il être universel ? Des chasseurs-cueilleurs à la flore intestinale inédite Ce peuple tanzanien se compose encore de tribus de chasseurs-cueilleurs, vivant probablement comme le faisaient nos ancêtres avant qu’ils ne maîtrisent l’agriculture.
Human microbiome A diagram of the microbiome of the skin Bacteria[edit] Populations of microbes (such as bacteria and yeasts) inhabit the skin and mucosa. Their role forms part of normal, healthy human physiology, however if microbe numbers grow beyond their typical ranges (often due to a compromised immune system) or if microbes populate atypical areas of the body (such as through poor hygiene or injury), disease can result. In 2012, some 200 researchers from some 80 research institutions comprising the Human Microbiome Project (HMP) Consortium have used advanced DNA-sequencing to identify and catalogue the thousands of microorganisms co-existing with humans. The same project examined the diversity of microbial communities present in multiple sites on the human body, using some 200 healthy persons and examining 18 sites on the body. Escherichia coli (a.k.a. The vaginal microflora consist mostly of various lactobacillus species. Archaea[edit] Fungal flora[edit] Anatomical areas[edit] Skin flora[edit]
Mais il a mal … R. 3 ans arrive à la Maison Médicale de Garde à 22h accompagné de son père. « - Bonsoir! Qu’est ce… - Alors hier, on a attendu 7 heures aux urgences…et on est ressorti avec juste du doliprane, alors là, faut nous donner des antibiotiques … - Alors, ça c’est de la Première Phrase de Consultation qui met dans l ambiance! et qui soulève inévitablement un sentiment pas très emphatique chez moi … (quand c’est en italique, c’est que je l’ai pensé mais pas dit tout haut car je suis une professionnelle quand-même NDLR) -Alors, d’accord, donc bonsoir à nouveau, asseyez-vous, et racontez moi tranquillement ce qui lui arrive… -Il a besoin d’antibiotiques.. -EMPATHIE! - J’ai bien compris votre demande. - Il a de la fièvre depuis hier après-midi, hier aux urgences, après 7h d’attente, ils lui ont rien donné, tenez ( compte rendu des urgences), et il est toujours malade… - Il a toujours de la fièvre aujourd’hui? - Oui -Il avait combien de température aujourd’hui? -Et voilà … -Il a d’autres symptômes? - Etc etc
Microbiome Depiction of the human body and bacteria that predominate A microbiome is "the ecological community of commensal, symbiotic, and pathogenic microorganisms that literally share our body space."[1][2] This term was originally coined by Joshua Lederberg, who argued the importance of microorganisms inhabiting the human body in health and disease. Many scientific articles distinguish "microbiome" and "microbiota" to describe either the collective genomes of the microorganisms that reside in an environmental niche or the microorganisms themselves, respectively.[3][4][5] However by the original definitions these terms are largely synonymous. The human body contains over 10 times more microbial cells than human cells, although the entire microbiome only weighs about 200 grams (7.1 oz),[6][7] with some weight estimates ranging as high as 3 pounds (approximately 48 ounces or 1,400 grams). Introduction[edit] Case studies[edit] Studies in humans[edit] Animal studies[edit] Plant studies[edit] Autism[edit]
Surfaces that use "hacked" bacteria to detect dirt or clean themselves Buildings in the future could feature floors embedded with synthetic bacteria that eat dirt and clean your feet, according to this project by design student Tashia Tucker (+ slideshow). Called Synthetic Biology: The Future of Adaptive Living Environments, the project explores how synthetic biology could be used in architecture to create smart surfaces impregnated with bacteria. "I think within the next 10 years we will start to see these biologically designed surfaces being developed in labs, and within the next 15-20 years being available to the public," Tucker told Dezeen. Tucker simulated ways that bacteria might perform tasks such as cleaning, changing the properties of surfaces according the users' needs or alerting humans to the presence of toxic substances for the project, which she developed during a course at the Design Futures Lab at Drexel University in Philadelphia. Here's a short project description: Synthetic Biology: The Future of Adaptive Living Environments